Knee replacement surgery, also called knee arthroplasty, is routinely considered for the treatment of osteoarthritis of the knee joint. Partial knee replacement surgery has generated significant interest because it entails a smaller incision and faster recovery than traditional total joint replacement surgery.
When partial knee replacement is performed, the bone and cartilage on the end of the femur and top of the tibia are removed. This is performed using precise instruments to create exact surfaces to accommodate an implant. A knee replacement implant made of various biocompatible materials such as metal or plastic is then placed to function as a new knee joint.
The typical arthritic cartilage damage pattern is oval or oblong in shape; however, the current techniques only allow for a circular allograft bone plug implant, or for a metal or plastic oval or oblong implant. Thus, the circular shape of the allograft implant does not correspond to the oblong or oval shape of the defect.
There is a need for a non-circular shape implant to be extracted from a donor femur for use in a bone-saving osteoarthritis distal femur resurfacing procedure. Also needed are instruments and techniques that allow matching of the recipient's femoral size and curvature to that of a donor femur (and to cut the donor femur cartilage plug to the correct size, shape and depth).